Metal-drawing apparatus.



L. H. BRINKMAN.

METAL DRAWING APPARATUS.

APPLICATION FILED NOV- 21.1917.

Patented Nov. 4, 1919.

til i" ll? LOUIS H. BRINKMAN, OF GLEN RIDGE, NEW JERSEY, ASSIGNOR TO BALL ROLLED TUBE I CORPORATION, A CORPORATION OF NEW YORK.

METAL-DRAWING APPTUS.

Specification of Letters Patent.

Patented Nov. 4, 1919..

Application filed November 21, 1917. Serial No. 203,121.

Glen Ridge, county of Essex, State of ew Jersey, have invented new and useful Improvements in Metal-Drawing Apparatus, of which the following is a specification.

This invention relates-to means for drawing down metal tubes.-

One object of the invention is to hold the tube being drawn in proper position with relation to a mandrel within the tube and a die outside the tube, the die and mandrel being relatively rotatable and also relatively movable axially.

Where the tubeis placed on a relatively non-rotatable mandrel which is then forced endwise through a rotating ball die or the like, the tube is moved endwise with the mandrel by reason of having its end peened down over the end of the mandrel. With such an arrangement, however, the turning die is apt to cause the tube to turn on the mandrel with the result that the drawing operation will not be properly performed. A further object of the invention is, therefore, to provide means for preventing the turning of the tube on the mandrel.

In apparatus Where the tube is forced through a die byengagement with a mandrel as just described, itis desirable that, after a length of tube has been drawn, it should be capable of being stripped off the mandrel by a device which engages the tube, the device and mandrel being so relatively moved that the tube passes ofi one end of the mandrel. It is a further object of the invention to provide means of the character above referred to which shall permit the ready stripping of the drawn tube from the mandrel.

Other and ancillary objects of the invention will appear hereinafter.

In the accompanying drawings, which illustrate the invention,

Figure 1 is a side elevation of apparatus embodying the invention;

Fig. 2 is a view partly in side elevation and partly in central longitudinal section, on an enlarged scale, of a portion of the apparatus of Fig.1;

Fig. 3 is a section on the line 33 of Fig. 2, and

Fig. 4 is a section on the line H of Fig. 1, on an enlarged scale.

Referring tothe drawings, and particu- -larly to Figs. 1 and 2, 1 is a platform or table on which is mounted a rotar electric motor 2 on the frame of which is 1ournaled the ball die mechanism 3, as hereinafter referred to. To the left of the mechanism is provided a furnace, such as a gas furnace 41: mounted on the legs 5 and having a series of gas pipes 6. This heater is hollow so as to permit the insertion of a mand'rel 7 therethrough when the tubes are drawn and so as to receive the tube 8 to be heated and drawn. The mandrel 7 may be simply a cylindrical rod secured at one end to the crosshead 7 sliding in guides 8 and 9. The crosshead is secured to the piston of a hydraulic cylinder 9 by the rod 10, whereby the mandrel and tube to be drawn are forced through the die, the crosshead preventing rotation of the mandrel. The mandrel is adapted to extend through the furnace to the ball die mechanism proper, and through the ball die mechanism to the extent to which it is desired to draw the tube through the die. On the other hand the structure is such that the mandrel may be Withdrawn to such extent as ma; be necessary to give the desired travel 0 the tube through the die and permit the tube to be put in place upon the mandrel.

As to the die mechanism, a hollow spindle 10 is journaled in a ring 11 fitting in.

relatively adjustable die cheek plates 15 and 16 are secured, the cheek plate 16 being preferably threaded into the die block 14, the. cheek plate 15 being keyed to said die block so as to slide in and out therein. The adjacent surfaces of the two cheek plates form a raceway for the die balls 17 and the balls are retained in this raceway by means of a cage 18. The check plate secured to the die block 14, rotates therewith, but the cheek plate 15 is so keyed to the block that it may slide longitudinally therein for the purpose of forcing the balls nearer to or permitting them to recede farther from the axis of the die, whereby the diameter of the die may be varied. It will be seen that the balls are forced inwardly or permitted to move outwardly according as the cheek plate 15 is moved toward or away from the cheek plate 16. The adjustment of the cheek plate 15 is accomplished by means of an adjusting device 19 having an annular flange portion 20 threaded on to an annular frame 21 keyed to the projection 12 on the motor frame. The adjusting device, which is in the form of a cap, has an end portion 22 surrounding the end of the cheek plate 15 and is provided with an opening 23 in alinement with the hollow spindle 10.

The end portion 22 of the adjusting device is intended to thrust inwardly against the cheek plate 15 and in order to avoid friction between said device and this check plate in adjusting the die while the machine is in operation, ball bearings 24 are provided between the cheek plate and the adjusting device; also ball bearings 25 between the inner end of the die block 14 and the adjacent wall of the annular frame 21 for taking up the thrust of the die balls which will be exerted through the die block and said bearings against the frame of the motor.

The adjusting device 19 may be adjusted by a handle or pin (not shown) which may be inserted into holes 26 distributed around the circumference of the flange 20 of the adjusting device and by this means the device may be'screwed in and out along the annular threaded extension 27 of the frame 21.

If it is desired to reduce the diameter of the die, the operator inserts the handle or pin into one of the holes 26 and turns the adjusting cap 19 in a direction to move it toward the motor. Thereupon the inward thrust of the cap upon the cheek plate 15 causes the same to be moved inwardly, forces its tapered surfacev against the die balls which are moved inwardly and the diameter of the die reduced. Conversely if it is desired to enlarge the die diameter, the operator rotates the adjustable cap in the opposite direction. Cheek plate 15 is thereby relieved of the thrust so that when the tube is pulled against the die balls they are forced outwardly thereby shifting the cheek plates against theadjusting cap. The balls are thus permitted to move radially outward and the diameter of the die is increased.

Upon' the annular flange 20 may be secured a graduated scale 28 over which moves a pointer 29 fixed to the frame 21. By suitably calibrating this scale, the relative positions of the ball holding parts and consequently the diameter of the die may be indicated so that the adjustment of the diameter of the die to a desired value may be acoomplished without reference to the die itself and consequently without shutting down the machine.

The armature of the electrical driving motor is mounted on an extension 30 of the hollow spindle 10, the two parts of the spindle being provided with flanges 31 secured together by bolts 32.

To cool the die parts, particularly the balls, and to wash away any scale which may have found its way into the ball raceway a cooling fluid is introduced into the raceway in contact with the balls and the centrifugal force occasioned by the rotation of the die prevents the flowing or dripping of the water into contact with the .hot tube being drawn.

In the apparatus shown, the die cheek plates 15 and 16 which form the raceway between them for the die balls, are so ar- The outer end of the cheek plate 15 provided with an annular flange 35 projecting radially inward so that the opening through the cheek plate is of less diameter than the inner diameter of the hollow spindle 10. A suitable pipe 36, projecting through the opening of the cheek plate, discharges the cooling fluid, which may be water, into the raceway, just within the annular flange of-the cheek plate. The fluid is thus delivered into the rotating parts at a point nearer to the center of rotation than the inner surface of the spindle. The centrifugal force thus creates a slight head so that the water is caused to flow from the point of delivery from the pipe 36 across the 40farevents flow'between the arts 14 and 16. v

the free end of the man rel are formed grooves 41. When the end of the tube to be drawn is peened down over the end of the mandrel in order thatit may be carried forward by the mandrel, as it is forced end- Wise through the die, the .metal will be driven into the groovesso that relative turning of the mandrel and tube is prevented. A strip per for pushing thetube endwise ofi the free end of'the mandrel, is provided, and

consists of the fork member 42 pivoted at 43 in the standards 44.. Upon this stripper 42 is formed a lug 45. When, as viewed in Figs. 1 and 2, it is attempted to move the stripper 42 in' a direction to the left, such movement is prevented by the lug 45 coming against a stop 46 on the standard 44. The

stripper may, however, swing in the opposite direction so that the tube and mandrel may be pushed to the right (see Figs. 1 and 2) the stripper riding upon the tube as in-' dicated clearly in Fig. 2. When the section of tube being operated upon has passed beyond the stripper as shown in Fig. 1, the

stripper will then fall into vertical position. Withdrawal of the mandrel, that is movement to the left in Fig. 1, will now bring the rearward end of the tube against the stripper 42, which, being unable to swing to the left, will block the passage of the tube and consequently the mandrel will be withdrawn from it. It will be noted that this stripping operation is not interfered with by the means for preventing rotation of the tube and mandrel.

In the operation of the machine, the mandrel is withdrawn by the hydraulic cylinder to such an extent that the tube to be drawn may be slid upon it. The end of the tube is then peened down over the free end of the mandrel, this operation driving the metal of the tube into the grooves 41 so that relative rotation of the mandrel and the tube is prevented. The mandrel is then forced slowly to the right (see Fig. 1) and, the tube being suitably heated at its successive sections by passing through the furnace 4, the end of the mandrel and tube enter within the working balls of the die and the travel of the mandreland die to the right is continued until the section of the tube being drawn has passed beyond the stripper 42. The stripper will then fall behind the rearward end of the tube and, the mandrel being drawn to the left, (Fig. 1) the 'rear end of the tube will come against it and the tube will be stripped off the mandrel as the latter is drawn toward the left (Fig. 1).

While the invention has been illustrated in what is considered its best embodiment, it may have other embodiments without departing from its spiritand is not therefore limited to the structure shown in the drawings, the appended claims pointing out the invention in accordance with the patent statutes.

What I claim is 1. In a tube drawing apparatus, the combination with relatively movable members comprising a mandrel and a die encircling said mandreL said die and mandrel being relatively rotatable, said mandrel having a free end, of means for relatively rotating said die and mandrel, means at'the free end of said mandrel for preventing relative rotation of the tube being drawn and the mandrel, and means at the other end of the ldnandrel for forcing it endwise through the 2. In a tube drawing apparatus, the combination with relatively movable members comp-rising a mandrel and a die encircling said mandrel, said die and .mandrel being rotatable, said mandrel having a free end, of means for relatively rotating said die and mandrel, means at the free end of said mandrel for preventing relative rotation of the tube being drawn and the mandrel, but permitting the tube to be stripped endwise off the mandrel, and means at the other end of the mandrel for forcing it endwise through the die.

3. In a tube drawing apparatus, the combination with relatively movable members comprising a mandrel'and a die encircling said. mandrel, said die and mandrel being relatively rotatable, said mandrel having a free end and grooves or recesses in the free end into which the metal of the tube is adapted to enter to prevent relative rotation of the mandrel and tube, of means for relatively rotating said die and mandrel and means at one end of the mandrel for forcing it endwise through the die.

4. In a tube drawing apparatus, the combination with relatively movable mem bers comprising a mandrel and a die encircling said mandrel, said die and mandrel being rotatable, said mandrel having a free end, of means for relatively rotating said die and mandrel, means at the free end of said mandrel for preventing relative rotation of the tube being drawn and the mandrel, but permitting the tube to be stripped endwise off the mandrel, and means at the other end of the mandrel for forcingport, said mandrel having a free end and grooves or recesses in said free end into which the metal of the tube is adapted to enter to prevent relative rotation of the tube and mandrel; a fluid pressure means at the other end of said mandrel for forcing it endwise through the die; and means for stripping the tube endwise off the free end of the mandrel.

In testimony whereof I have signed this 10 sgegification this 13th day. of November, 1 1

LOUIS H. BRINKMA'N. 

